In prokaryotes, the nucleotide exchange factor GrpE and the chaperone DnaJ are required for nucleotide binding of the molecular chaperone DnaK [9103205]. The DnaK reaction cycle involves rapid peptide binding and release, which is dependent upon nucleotide binding. DnaJ accelerates the hydrolysis of ATP by DnaK, which enables the ADP-bound DnaK to tightly bind peptide. GrpE catalyses the release of ADP from DnaK, which is required for peptide release. In eukaryotes, GrpE is essential for mitochondrial Hsp70 function, however the cytosolic Hsp70 homologues are GrpE-independent.

GrpE binds as a homodimer to the ATPase domain of DnaK, and may interact with the peptide-binding domain of DnaK. GrpE accomplishes nucleotide exchange by opening the nucleotide-binding cleft of DnaK. GrpE is comprised of two domains, the N-terminal coiled coil domain, which may facilitate peptide release, and the C-terminal head domain, which forms part of the contact surface with the ATPase domain of DnaK. The head domain is comprised of six short beta strands with a limited hydrophobic core.

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry
out SCOP domain assignments to all genomes at the superfamily level.

Alignments of sequences to 1 models
in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical
are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.

Browse and view proteins in genomes which have
different domain combinations including a Head domain of nucleotide exchange factor GrpE domain.

Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.

There are 1 hidden Markov models representing the Head domain of nucleotide exchange factor GrpE superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.